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5261 libm should stop using synonyms.h
5298 fabs is 0-sized, confuses dis(1) and others
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Approved by: Gordon Ross <gwr@nexenta.com>
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--- old/usr/src/lib/libm/i386/src/exp.s
+++ new/usr/src/lib/libm/i386/src/exp.s
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21 /*
22 22 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
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23 23 */
24 24 /*
25 25 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
26 26 * Use is subject to license terms.
27 27 */
28 28
29 29 .file "exp.s"
30 30
31 31 #include "libm.h"
32 32 LIBM_ANSI_PRAGMA_WEAK(exp,function)
33 -#include "libm_synonyms.h"
34 33 #include "libm_protos.h"
35 34
36 35 ENTRY(exp)
37 36 movl 8(%esp),%ecx / ecx <-- hi_32(x)
38 37 andl $0x7fffffff,%ecx / ecx <-- hi_32(|x|)
39 38 cmpl $0x3fe62e42,%ecx / Is |x| < ln(2)?
40 39 jb .shortcut / If so, take a shortcut.
41 40 je .check_tail / |x| may be only slightly < ln(2)
42 41 cmpl $0x7ff00000,%ecx / hi_32(|x|) >= hi_32(INF)?
43 42 jae .not_finite / if so, x is not finite
44 43 .finite_non_special: / Here, ln(2) < |x| < INF
45 44 fldl 4(%esp) / push x
46 45 subl $8,%esp
47 46 /// overhead of RP save/restore; 63/15
48 47 fstcw (%esp) /// ; 15/3
49 48 movw (%esp),%ax /// ; 4/1
50 49 movw %ax,4(%esp) /// save old RP; 2/1
51 50 orw $0x0300,%ax /// force 64-bit RP; 2/1
52 51 movw %ax,(%esp) /// ; 2/1
53 52 fldcw (%esp) /// ; 19/4
54 53 fldl2e / push log2e }not for xtndd_dbl
55 54 fmulp %st,%st(1) / z = x*log2e }not for xtndd_dbl
56 55 fld %st(0) / duplicate stack top
57 56 frndint / [z],z
58 57 fucom / This and the next 3 instructions
59 58 fstsw %ax / add 10 clocks to runtime of the
60 59 sahf / main branch, but save about 265
61 60 je .z_integral / upon detection of integral z.
62 61 / [z] != z, compute exp(x)
63 62 fxch / z,[z]
64 63 fsub %st(1),%st / z-[z],[z]
65 64 f2xm1 / 2**(z-[z])-1,[z]
66 65 fld1 / 1,2**(z-[z])-1,[z]
67 66 faddp %st,%st(1) / 2**(z-[z]) ,[z]
68 67 .merge:
69 68 fscale / exp(x) ,[z]
70 69 fstp %st(1)
71 70 fstcw (%esp) / restore RD
72 71 movw (%esp),%dx
73 72 andw $0xfcff,%dx
74 73 movw 4(%esp),%cx
75 74 andw $0x0300,%cx
76 75 orw %dx,%cx
77 76 movw %cx,(%esp)
78 77 fldcw (%esp) /// restore old RP; 19/4
79 78 fstpl (%esp) / round to double
80 79 fldl (%esp) / exp(x) rounded to double
81 80 fxam / determine class of exp(x)
82 81 add $8,%esp
83 82 fstsw %ax / store status in ax
84 83 andw $0x4500,%ax
85 84 cmpw $0x0500,%ax
86 85 je .overflow
87 86 cmpw $0x4000,%ax
88 87 je .underflow
89 88 ret
90 89
91 90 .overflow:
92 91 fstp %st(0) / stack empty
93 92 push %ebp
94 93 mov %esp,%ebp
95 94 PIC_SETUP(1)
96 95 pushl $6
97 96 jmp .error
98 97
99 98 .underflow:
100 99 fstp %st(0) / stack empty
101 100 push %ebp
102 101 mov %esp,%ebp
103 102 PIC_SETUP(2)
104 103 pushl $7
105 104
106 105 .error:
107 106 pushl 12(%ebp) / high x
108 107 pushl 8(%ebp) / low x
109 108 pushl 12(%ebp) / high x
110 109 pushl 8(%ebp) / low x
111 110 call PIC_F(_SVID_libm_err)
112 111 addl $20,%esp
113 112 PIC_WRAPUP
114 113 leave
115 114 ret
116 115
117 116 .z_integral: / here, z is integral
118 117 fstp %st(0) / ,z
119 118 fld1 / 1,z
120 119 jmp .merge
121 120
122 121 .check_tail:
123 122 movl 4(%esp),%edx / edx <-- lo_32(x)
124 123 cmpl $0xfefa39ef,%edx / Is |x| slightly < ln(2)?
125 124 ja .finite_non_special / branch if |x| slightly > ln(2)
126 125 .shortcut:
127 126 / Here, |x| < ln(2), so |z| = |x*log2(e)| < 1,
128 127 / whence z is in f2xm1's domain.
129 128 fldl 4(%esp) / push x
130 129 fldl2e / push log2e }not for xtndd_dbl
131 130 fmulp %st,%st(1) / z = x*log2e }not for xtndd_dbl
132 131 f2xm1 / 2**(x*log2(e))-1 = e**x - 1
133 132 fld1 / 1,2**(z)-1
134 133 faddp %st,%st(1) / 2**(z) = e**x
135 134 ret
136 135
137 136 .not_finite:
138 137 / Here, flags still have settings from execution of
139 138 / cmpl $0x7ff00000,%ecx / hi_32(|x|) > hi_32(INF)?
140 139 ja .NaN_or_pinf / if not, x may be +/- INF
141 140 movl 4(%esp),%edx / edx <-- lo_32(x)
142 141 cmpl $0,%edx / lo_32(x) = 0?
143 142 jne .NaN_or_pinf / if not, x is NaN
144 143 movl 8(%esp),%eax / eax <-- hi_32(x)
145 144 andl $0x80000000,%eax / here, x is infinite, but +/-?
146 145 jz .NaN_or_pinf / branch if x = +INF
147 146 fldz / Here, x = -inf, so return 0
148 147 ret
149 148
150 149 .NaN_or_pinf:
151 150 / Here, x = NaN or +inf, so load x and return immediately.
152 151 fldl 4(%esp)
153 152 fwait
154 153 ret
155 154 .align 4
156 155 SET_SIZE(exp)
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